Synchronous serial communication is serial communication wherein data is sent or received in synchronization with a clock. A synchronous serial interface (hereinafter abbreviated to “SSI”) is widely used as a standard interface between a master and a slave for industrial applications.
For example, JP H5-63754A discloses a signal transmitter that serially transmits an NRZ (Non Return to Zero) signal stream from a transmitting circuit to a receiving circuit in synchronization with a clock signal stream. This signal transmitter executes horizontal and vertical parity checks. The signal transmitter further generates a signal that indicates detection of a header, a reception error signal, or a reception end signal.
JP H5-63754A is an example of background art.
However, conventionally, as disclosed in JP H5-63754A, bit inversion or the like caused by external noise or the like has only been dealt with by parity checks. Therefore, cases where there is a significant change in the data, such as a change in multiple bits caused by external noise, conventionally could not be dealt with.
To address this issue, it is conceivable to allow the synchronous serial interface to perform transmission using a more sophisticated protocol and impart data checking functionality, such as an FCS (Frame Check Sequence), to the synchronous serial interface. However, this approach requires high-speed bidirectional communication and results in an increase in device cost.